Plasmonic Biosensors

As is said, disease is “written in blood.” In this piece, the “writing” is in exosomes—those waste management vesicles of protein and RNA found in blood and urine. Researchers at Aalto University in Helsinki have created a biosensor that detects exosomes related to disease from plasmons generated when light hits a black metal surface. The surfaces to which the liquid specimen adhere contain silver nanoparticles covered with “various dielectrics of AlN, SiO2 and the composites . . .enhance the reflectivity contrast of various colours at a normal angle of incidence.” It is by color, then, that the sensor indicates a disease state. MORE